This invention relates to a process for cleaning the face of a spinneret with a wipe stick.
In conventional melt spinning of synthetic fibers from thermoplastic polymers, polymeric material heated to a plastic, flowable state is forced under pressure through spinneret capillaries to form filaments. After suitable further treatment, such as cooling and stretching, the filaments are wound onto packages or formed into tows for further processing. During the extrusion process, deposits of polymeric and/or degraded polymeric ingredients accumulate on the exit face of the spinneret surrounding each capillary. Periodic wiping (or scraping) the face of the spinneret by an operator with a hand held tool referred to as a wipe stick removes the accumulations and prolongs the period of useful spinning before major disassembly and cleaning of the spinneret pack becomes necessary.
Wiping of spinnerets is well known and routinely practiced in melt-spinning operations. It is definitely an art, and variations in wiping technique among operating personnel lead to differences in uniformity and completeness of the wiping operation. Thus, subsequent spinning performance is dependent on the skill of the operator.
Recent developments in the melt spinning art have added to the difficulty of satisfactory spinneret wiping, even by skilled operators. It has become rather common to surround the spinneret exit with shrouds, heaters, and/or devices for blanketing the face of the spinneret with an inert gas. To the extent that these devices limit access to the spinneret or restrict freedom of movement, the difficulty in providing satisfactory wipes is multiplied.